Pith. sign in

REVIEW 6 cited by

ENCORE: An $\mathcal{O}(N_{\rm g}^2)$ Estimator for Galaxy $N$-Point Correlation Functions

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2105.08722 v3 pith:FTSN7U64 submitted 2021-05-18 astro-ph.IM astro-ph.COgr-qcphysics.comp-ph

classification astro-ph.IMastro-ph.COgr-qcphysics.comp-ph
keywords functionsgalaxyalgorithmmathcalmathrmsurveyappliedapproach
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
abstract

We present a new algorithm for efficiently computing the $N$-point correlation functions (NPCFs) of a 3D density field for arbitrary $N$. This can be applied both to a discrete spectroscopic galaxy survey and a continuous field. By expanding the statistics in a separable basis of isotropic functions built from spherical harmonics, the NPCFs can be estimated by counting pairs of particles in space, leading to an algorithm with complexity $\mathcal{O}(N_{\rm g}^2)$ for $N_{\rm g}$ particles, or $\mathcal{O}\left(N_\mathrm{FFT}\log N_\mathrm{FFT}\right)$ when using a Fast Fourier Transform with $N_\mathrm{FFT}$ grid-points. In practice, the rate-limiting step for $N>3$ will often be the summation of the histogrammed spherical harmonic coefficients, particularly if the number of radial and angular bins is large. In this case, the algorithm scales linearly with $N_{\rm g}$. The approach is implemented in the ENCORE code, which can compute the 3PCF, 4PCF, 5PCF, and 6PCF of a BOSS-like galaxy survey in $\sim$ $100$ CPU-hours, including the corrections necessary for non-uniform survey geometries. We discuss the implementation in depth, along with its GPU acceleration, and provide practical demonstration on realistic galaxy catalogs. Our approach can be straightforwardly applied to current and future datasets to unlock the potential of constraining cosmology from the higher-point functions.

Discussion (0). Sign in to comment.

Forward citations

Cited by 6 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Primordial Physics in the Nonlinear Universe: Revealing the oscillating halo bias from cosmological collider models

    astro-ph.CO 2026-07 accept novelty 7.0 of 10

    A binning-based IC method yields the first N-body measurements of oscillating halo bias from cosmological collider bispectra, with mass- and assembly-dependent phases fit by peak-background-split theory.

  2. No evidence for parity violation in BOSS

    astro-ph.CO 2024-07 unverdicted novelty 7.0 of 10

    New statistics applied to BOSS data show the reported parity violation signal is consistent with zero after accounting for eight-point correlation function mismatch between data and mocks.

  3. Measuring local primordial non-Gaussianity from the clustering of DESI DR1 LRGs and QSOs

    astro-ph.CO 2026-06 unverdicted novelty 6.0 of 10

    Reports first config-space f_NL measurement from DESI DR1 LRG/QSO 2pcf, yielding joint f_NL = -3^{+12}_{-12} at 68% CL using simulation-based modeling and imaging systematics mitigation.

  4. Parity-odd Four-Point Correlation Function from DESI Data Release 1 Luminous Red Galaxy Sample

    astro-ph.CO 2025-12 accept novelty 6.0 of 10

    The parity-odd four-point correlation function measured in DESI DR1 LRGs is consistent with zero after correcting for survey-induced covariance mismatches.

  5. Measurement of Parity-Violating Modes of the Dark Energy Spectroscopic Instrument (DESI) Year 1 Luminous Red Galaxies' 4-Point Correlation Function

    astro-ph.CO 2025-08 conditional novelty 6.0 of 10

    DESI's first parity-violation search shows a strong auto-correlation signal that disappears when the sky is split into patches, pointing to underestimated mocks' variance rather than new physics.

  6. A $(D_\tau,D_x)$-manifold with $N$-correlators of $N_t$-objects

    physics.gen-ph 2022-08 unverdicted novelty 4.0 of 10

    Constructs a (D_τ,D_x)-manifold with N-correlators of N_t-objects using field theory, topology, algebra, statistics and Fourier transforms, and discusses applicability across cosmological scales.

Pith tools